<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Curved Shape</title>
    <style>
        body{
            background: #767775;
        }
        .box-show {
            width: 100%;
            border-bottom: 1px solid #56A7FB;
            border-bottom: 1px solid;
            border-image: -webkit-linear-gradient(30deg, rgba(255, 255, 255, 0.00) 0%, #56A7FB 20%, rgba(255, 255, 255, 0.00) 99%) 2 2 2 2;
            border-image: -moz-linear-gradient(30deg, rgba(255, 255, 255, 0.00) 0%, #56A7FB 20%, rgba(255, 255, 255, 0.00) 99%) 2 2 2 2;
            border-image: linear-gradient(30deg, rgba(255, 255, 255, 0.00) 0%, #56A7FB 50%, rgba(255, 255, 255, 0.00) 99%) 2 2 2 2;
        }

        .box {
            border-right: 1px solid;
            border-image: -webkit-linear-gradient(#F8F8F8, #AAA, #F8F8F8)1 10 1;
            /* 控制边框颜色渐变 */
            border-image: -moz-linear-gradient(#F8F8F8, #AAA, #F8F8F8)1 10 1;
            border-image: linear-gradient(#F8F8F8, #AAA, #F8F8F8)1 10 1;
            /* 标准的必须写在最后 */
        }
    </style>
</head>

<body>
    <div class="box-show"> </div>
    <div class="box"></div>
</body>

</html>